Can sealing machine



Nov. l7, 1942. HQTHERSALL, 2,301,949

CAN SEALING MACHINE riled June 7. 1939 4 Shets-Sheet 1 ATTORN EY Nov. 17, 1942.

J. M, HOTHERSALL CAN SEALING MACHINE Filed June 7, 1939 4 Sheets-Sheet 2 NOV. 17, 1942. J. M, HOTHERSALL 25301 949 CAN SEALING MACHINE Filed June 7, 1939 4 Sheets-Sheet 4 Patented Nov. 17, 1942 UNITED STATES PATENT OFFICE CAN SEALING MACHINE John M. Hothersall, Brooklyn, N. Y., assignor .to American Can Company, New York, N. Y., a corporation of New Jersey Application June 7, 1939, Serial No. 277,914

9 Claims.

The present invention relates to a machine for sealing containers or cans having vent holes provided therein and has particular reference to sealing the hole with a rubber plug or the like.

An object of the invention is the provision of a machine for sealing filled cans having an attached cover provided with a vent hole wherein a rubber plug is compressed into a dimension smaller than the vent hole and is then inserted into the hole and permitted to expand to its original size so that it will fill and hermetically seal the hole.

Another object is the provision of such a machine wherein the plug is cut from a string of rubber and is forced into sealing position in the hole to be sealed, by pressure exerted onto it through another plug so that proper insertion of the first plug may be obtained.

Another object is the provision of a machine of this character wherein the head space in the can may be vacuumized or vacuumized and gassed through the vent hole before it is sealed with the rubber plug.

Numerous other objects and advantages of the invention will 'be apparent as it is better understood from the following description, which, taken in connection with the accompanying drawings, discloses a preferred embodiment thereof.

Referring to the drawings:

Figure 1 is a top plan view of a can sealing machine embodying the instant invention, parts being broken away;

Fig. '2 is a sectional view taken substantially along the longitudinal line 2-2 in Fig. l, with parts broken away;

Fig. 3 is a side elevation of the upper portion of the machine as viewed substantially from an observation position indicated by the line 3-3 in Fig. 1, with parts broken away;

Fig. 4 is a sectional detail taken substantially along the transverse line 44 in Fig. 1;

Fig. 5 is a horizontal section taken substantially along the broken line 5-5 in Fig. 2, with parts broken away;

Fig. 6 is an enlarged sectional detail taken substantially along the line 6-6 in Fig. 5, the view also showing in section the upper end of a can to be sealed;

Fig. '7 is a sectional view of the upper end of a sealed can drawn to the same scale as the can of Fig. 6; and

Fig. 8 is a wiring diagram of the electric apparatus used in connection with the machine.

til

A a preferred embodiment of the instant in- 5 vention the drawings illustrate a machine in which filled and closed cans A (Fig. '7) having covers B, with vent holes C preferably in the center thereof, are Vacuumized and gassed and are then sealed with rubber plugs D which are inserted under pressure into the holes so that the plugs fill and hermetically seal the cans. The vent hole in each can is preferably located in a counter-sunk panel E of the cover so that the inserted plug will be protected against displacement during subsequent handling of the sealed can.

In the machine, the cans A to be sealed are received in a continuously moving single line or procession, inspaced relation and are conveyed along a curved path of travel under a rotating unit G provided with sealing heads H (Fig. 2) which move over the path of travel of the cans. While passing along this path of travel, a can is lifted into engagement with its head and. while in raised position, a string of rubber J is fed into the head. The plug D is cut off from the string and this plug is then transferred into vertical alignment with the vent hole in the can.

During this preparation of the plug D, the can is preferably vacuumized and gassed. Near the end of the gassing operation, the aligned plug D is compressed into smaller diameter than the vent hole in the can and is then forced into place within the hole. This takes place upon completion of gassing, the inserted plug being permitted to expand so that it fills and hermetically seals the hole, as hereinbefore mentioned. The sealed can is then moved down, away from the head and is discharged from the machine to a suitable place of deposit.

Feeding of the cans A into the machine is preferably effected by way of an endless feed-in conveyor belt II (Figs. 1 and 4) The machine end of the belt takes over a pulley I'2 mounted on a belt shaft I3 journaled in bearings I4 formed in a main frame I5 which supports the various parts of .the machine. The advancing cans are maintained in'line by a pair of spaced and parallel guide rails l6 between which theypass. The guide rails are secured to extensions I! of the main frame which are disposed adjacent the path of travel of the belt.

The conveyor belt shaft I3 is rotated by a gear 2| which meshes with a gear 22 (Fig, 4) keyed onto the outer end of a short shaft 23 journaled in a bearing 24 formed in the main frame I5. The inner end of the shaft carries a bevel gear 25 which meshes with and is driven by bevel gear teeth of a composite bevel spur gear-21 (see also Fig. 2) keyed onto the lower end of a vertically disposed star wheel shaft 23. The star wheel shaft is journaled in spaced upper and lower bearings 29 of the main frame 15.

The composite bevel, spur gear 21 is driven by a gear M which meshes with the spur gear teeth of the composite gear and which is keyed onto the lower end of a vertically disposed table sleeve 32 rotatable on a stationary post 33. The lower end of the post is bolted into a holding block 34 formed in a base 35 on which the main frame I is supported.

Keyed onto the sleeve 32 adjacent the gear- M is a bevel gear 3'! which meshes with, and is driven by a main driving pinion 33 secured to the inner end of a main drive shaft 39. The drive shaft is journaled in a bearing 4! formed in the machine base 35. This is the main drive shaft for the machine and is rotated from any suitable source of power.

As the cans A entering the machine reach the machine end'of the conveyor belt ll they are swept off onto a stationary table '43 (Figs. 1 and 2) which is provided at the top of the frame l5. This sweeping action is'effected by an entrance star wheel 44 which is carried on the upper end of the star wheel shaft 23 and which is rotated thereby in time with the other moving parts of the machine. Thestar wheel is formed with curved prongs 45 which swing across the conveyor belt I l as the star wheel rotates and which engage the cans thereon, transferring them to the table.

A can A, received on the table 43, is advanced by the star wheel along a curved path of travel and is brought into place onto a moving lifter plate 48 (Fig. 2). There are a plurality of these lifter plates, preferably four in number, which are disposed in recesses 49 formed in a rotatable table 5| movable in an opening 52 provided in the stationary table 43. Table 5! is a part of the rotating unit G.

The rotatable table 5| may be formed as a part of the table sleeve 32 hereinbefore mentioned and is supportedon a ball bearing unit 55. secured in place on the sleeve by a nut 55. The outer race of the ball-bearing unit is confined in a seat 55 provided in a stationary hub 57 formed in a horizontal web 58 of the frame l 5. A ball thrust bearing 59, disposed at the lower end of the sleeve andseated on the top of the holding block 34, helps support the entire rotating unit G including the table and sleeve and also provides for free turning around the post 33. The table and its sleeve are rotated in time with the other moving parts of the machine through the bevel gear 31.

The cans A received on the lifter plates 48 are centralized thereon and retained in position by a turret 62 (Fig. 2) having spaced pockets 63 which align with the lifter plates. This turret is keyed to a vertical upper sleeve extension 64 of the rotatable table 5!. The turret is also a part of the rotating unit G and thus rotates with the table. The turret and the rotatable table may thus be described as carrying the cans around the post 33 in a predetermined circular path of travel.

During this travel around the post 33, the cans are raised vertically in their turret pockets by the corresponding lifter plate '48. For this purpose each lifter plate is formed on the upper end of a vertically disposed rod 61 which is carried in a bearing 68 depending from the rotatable table ing ring 8| (Figs. 2 and 6).

" mosphere.

on which are mounted inner and outer cam rollers 72, 73. These rollers traverse and operate against inner and outer stationary ring cams M, 15. The outer ring cam is bolted to the horizontal web 58 of the frame and the inner cam is secured in a seat 16 formed in a base ll of the outer cam as clearly shown in Fig. 2.

In its uppermost position a can A on its raised lifter plate 48, engages a closing or sealing head H, hereinbefore mentioned. There are preferably four of these sealing heads H, one being disposed above each lifter plate and in vertical alignment therewith. These heads are carried around with the lifter plates and with the rotating table 5|.

Theouter upper edge of the raised can A in the sealing head H contacts with a rubber seal- This ring is secured in an annular seat 82 provided in a disc 83 (see also Fig, 5) formed integrally with the table upper sleeve extension 64. Hence the disc rotates with the table 5: and the lifter plates carried therein. The sealing ring thus engaging the end seam of the can, hermetically blocks off the space above the top end of the can from the outside at- It is while the can is thus held that its interior head space may be vacuumized and filled with an inert fluid such as carbon dioxide gas or the like by way of the vent hole C. While thus held it is sealed with the plug D, as hereinbefore 51. The lower end of the rod carries a pin H mentioned. The vacuumized and gassing opera tions will be more fully explained.

For this vacuumizin of the can a short vertical channel 86 (Fig. ,6) is provided for each sealing ring in the disc 83. The lower end of this channel communicates with the blocked 01f space between the disc and the top of the can. The upper end of the channel leads into a short horizontal passageway 87 which merges into a longer radial passageway 88 (see also Fig. 5) the inner end of which terminates adjacent the stationary post 33. These passageways are all formed in the disc 83.

Intermediate the length of the short horizontal passageway 81 there'is provided a cut oif valve pin 9i for opening and closing the passageway. The pin 9| is disposed in a vertical bore 92 formed partly in the disc 83 and partly in a sealing head bracket 94 which is bolted to the top of the disc. A compression spring 95 is interposed between the upper end of the bore and the upper end of the pin and thereby exerts a downward pressure on the pin. The pin is retained within the bore by a short cross pin 96 which is secured in the bracket and which extends across a groove 9'! formed in the side of the valve pin.

The lower end of the valve pin .9l normally projects down below .thecan sealing ring 8| and in this lowered position it blocks 01f the passageway 87 closing communication with the channel 88. However, when a can is lifted intoposition against the sealing ring, its can cover B, engaging the pin, lifts it against the resistance of its spring 95. This shifting of the pin brings a transverse valve port 93 formed therein into register with the passageway 87 and thereby opens the communication between it and the channel 86. The valve pin remains in this raised position as long as the can is held against the sealing ring 8 l As the sealing head H rotates around the sta-' of the passageway moves past and comes into' communication with a gassing groove I02 also formed in the outer surface of the post. Each groove extends around through approximately 45 degrees and the two grooves are thus in predetermined spaced relation.

The vacuum groove IOI communicates with an angularly disposed channel I34 (see also Fig. 2) which extends radially of and toward the center of the post and then up through the post to its top end where it joins into a pipe I threaded in the post. This pipe leads to a suitable source of vacuum such as a tank or pump.

In a similar manner the gassing groove I32 communicates with an angularly disposed radial and axial channel H11 in the lower end of the post. Channel I01 communicates with a pipe I08 which is threaded into the lower end of the post. This pipe leads to any suitable source of gas under pressure such as a tank or compressor.

Hence when the inner end of a radial passageway 88 comes adjacent the vacuum groove I8 I, air from the can A is emausted by way of the vent hole C, channel 86, valve port 98, passageways 81, 88, groove IOI, channel I84 and pipe I05. This line of communication is open for approximately one quarter rotation of the rotating unit G and is then out off as the inner end of the passageway 33 moves past the end of the vacuum groove.

Immediately following this vacuumizing operation the passageway 88 comes into communication with the gassing groove I02 and gas from the pipe I88 thereby flows through the channel I01, groove I02 and into the passageway 88 following back through the various passageways and channels in the reverse order given above until it passes through the vent hole C into the can head space. This gassing operation takes place during approximately a second quarter turn of the rotating unit G at the end of which the can is sealed and then discharged, as will be hereinafter explained.

The preparation of the plug D will now be explained. During the vacuumizing and gassing of a can A and while it is moving along its curved path of travel around the stationary post 33, the rubber plug D which is to be used in sealing the vent hole C of the can, is being prepared. It is brought into position above the hole in readiness for insertion, just before the can is discharged from the machine. The preparation of the plug begins even before a can is received in its turret pocket 63. The first step is the feeding into position of the string J of rubber, so that the plug D may be cut off therefrom. This feeding is as follows.

The string J of rubber is preferably brought from a supply reel the rubber being carried on a spool III (Figs. 1 and 2). There is one of these spools for each can pocket 63 of the turret 62. Eachspool is mounted on an axis or shaft H2 carried in a yoke bearing I I3 formed in a bracket H4. The brackets are bolted to a swivel plate H6 mounted on ball bearings H1 which are carried on the upper end of the stationary post 33 and are held in place by a lock nut H8 threaded on the post.

The plate [I6 rotates with the table 5I and disc 83. For this purpose, the plate is connected by depending rods H9 (see Fig. 3) and nuts I20 to an auxiliary plate I2I Plate I2I in its turn is clamped by half caps I22 (see also Figs. 2 and 5) to the upper ends of hollow upright columns I23 formed on the sealing head brackets 94. This auxiliary plate surrounds the stationary post 33 these being parts of the rotating unit G.

The string J of rubber as it comes off of each spool I I I, extends down through a guide hole I25 in its associated half cap I22 and then passes into a vertical bore I26 formed in the sealing head bracket 94. The lower end of the string is disposed between a pair of grooved feeding rollers I21 (see also Fig. 3) located in recesses I 28 formed in the head bracket 94.

The rollers I21 are mounted on short shafts I29 which are journaled in bearings formed in the bracket. One of the shafts carries a ratchet I3I (Fig. 2) which is operated by a pawl I32 (Fig. 3) mounted on a pawl arm I33. The inner end of the arm is free on the ratchet shaft. The opposite or outer end of the arm is connected by a link I35 to a slide block I36 which slides vertically on the hollow upright column I23 of the head bracket 94.

The slide block I36 is shifted on its slide column in time with the rotation of the rotatin unit G by a barrel cam I4I (Figs. 2 and 3). Cam MI is formed on a sleeve I42 which is keyed onto the stationary post 33 near the top. A cam roller I43 on each of the slide blocks I36 traverses and operates in a peripheral cam groove I44 of the cam I4I Hence as the unit G rotates around the cam, each slide block I36 slides first upwardly and then downwardly on its column I23 and thereby actuates the described pawl and ratchet members I32, I3I to rotate the feed rollers I21 intermittently to progressively feed increments of rubber string J downwardly therebetween. This intermittent downward movement or feed of the rubber string J occurs in that part of the cycle of rotation of the unit which in point of time is just prior to the receipt of a can A on its lifter plate 43. The rubber string is thus advanced in a downward direction through the bore I26. This feeding of the string J positions its lower end in readiness for cutting off in the formation of a plug D.

The lower end of the rubber string J of the unit under consideration is received in a slide member I5I (Figs. 2, .5 and 6). There are four of these slide members, each carried in a radial groove I52 formed in the top surface of the rotating disc 83. The outer end of each slide is substantially the same thickness as the desired length of .plug D. The inner end of the slide is considerably thicker than the outer end and carries a cam roller I53, which operates in a cam groove I54 of a stationary cam I55 formed on the cam sleeve I42. I

As the unit G rotates around the stationary post, each cam roller I53 traverses the cam groove I54 and moves its associated slide outwardly into an outer position and inwardly into an inner position. In the outer position, a small hole or pocket I 51 formed in the slide adjacent a central longitudinal slot I58, is disposed directly under the lower end of the bore I26. It is therefore in register with the end of the rubber string J. The lower end of the string enters the hole I51 when it is fed. down throughits bore I26.

A slide I5I with the inserted rubber string J are in this position when they come adjacent the can feed-in star wheel 44 (Fig. 5) in the movement of the rotating disc 83. As they pass the star wheel, that portion of the rubber string which is in the slide hole I51 is severed from the remainder of the string and the cut-off portion remains in the hole. It is this cut-off portion that constitutes the rubber plug D.

Cutting of the rubber string J is effected by a and rotates freely thereon on a loose collar I 24,

horizontal rotary knife or cutter IBI (seealso Fig. 2) which'is located just above the star wheel 44. The cutter is mounted on the lower end of a rotor shaft I62 of an electric motor I63 secured to a bracket I84 bolted to the side of the main frame I5. As the rotating disc 83 carries the slide past the spinning cutter, the latter passes through a horizontal clearance slot I69 in the head bracket 94 just above the slide and the cutter severs the string on a level with the top of the slide.

In conjunction with the sequence of operations it should be remembered that this cutting off of the plug D takes place just as a can to be sealed is deposited in its turret pocket 93 by the star wheel 44. The vacuumizing of the can as hereinbefore explained takes place immediately after this plug cutting operation. During vacuumizing and gassing of the can A, the plug D is carried by the slide to the center of the can and directly over the vent hole where it is in readiness for the sealing operation.

Sealing of the can is effected by elements associated with the sealing heads H which will now be described. The sealing elements of each sealing head include a plug confining and compressing sleeve I1I (Figs. 2 and 6) which is slidably mounted in a vertical bore I12 extending through the head bracket column I29. There are four of these sleeves, one for each turret pocket 63 and each sleeve is located directly over the center of a can in the pocket so that it will be in line with the vent hole of the can.

The upper end of each sleeve is confined in a sleeve block I14 which carries a cam roller I15 operating in a cam groove I19 of a stationary barrel cam I11 keyed to the post 33. The cam is held in position by a lock nut I18 threaded onto the post.

The lower end of the sleeve I1I extends down through the central slot I58 of the slide II, a clearance recess I19 being provided in the sleeve for this purpose. At its extreme bottom end the sleeve is shaped to fit within the countersunk panel E of the can cover. This lower portion of the sleeve is provided with a bore I82 which for the most part is slightly larger in diameter than the rubber plug D. At its upper end the bore I82 merges into a larger diameter concentric bore I83 which extends up through the center of the sleeve.

At its lower end the bore merges into a smaller diameter orifice I84 which is slightly smaller in diameter than the vent hole C in the can cover.

The bores I82, I83 and the orifice I84 are concentric with the hole I51 in the slide I5I when the latter is in its inward position over the vent hole C.

Within the sleeve I N there is disposed a plunger I89 which slides in the large bore 183. The lower end of the plunger is reduced in diameter in an end section I90 which has a sliding fit within the bore I82. The upper end of the plunger is retained in a plunger block I9I (Fig. 2) which carries a cam roller I92 operating in a cam groove I93 formed in the periphery of the barrel cam I11 and above the cam groove I16.

Hence as the sealing heads H advance around with the rotating unit G, the plunger cam rollers I92 and the sleeve cam rollers I traverse the stationary cam grooves and thus separately and relatively actuate the plunger and the sleeve relative to the head. column I 23. This actuation takes place after the gassing of the can head space is complete and when the can is ready to be sealed.

The plunger I89 first moves down within its bore I83 and in so doing its plunger end I98 passes through the hole I51 in the slide I5I. At the same time it pushes the plug D out of the hole and into the bore I82. This plunger eventually pushes the plug all the way down into the lower end of the sleeve and compresses it as it passes into the orifice bore I84, but this occurs during a second cycle.

It should be understood in explanation, that after the machine is once set in operation a plug D will always be left in a compressed condition in the orifice I84. The first plug which is cut.

and inserted in the hole I19 of the slide, as when first starting the machine, is not immediately in-- serted into the can vent hole. The placing of a plug into the vent hole is done subsequently and through pressure exerted on it through a following plug.

When a second plug is pushed into the bore I82 above the compressed plug in the orifice I84,

it is not immediately brought down into engagement with the lower compressed plug but remains for a time in spaced'relation therewith. This spacing of the upper and lower plugs is brought about by the simultaneous moving down of the sleeve I1I along with the plunger I89. The sleeve begins its descent after the upper plug has been removed from the slide I5I. This is done so that the upper plug will be fully in the bore I82. This lowering of the sleeve brings its lower end into tight engagement with the can cover B as shown to the right in Fig. 2.

While the sleeve is held in this lowered position by the cam groove I 16 of the cam I11, the plunger I89 continues to descend and this brings the upper plug down on top of the compressed plug in the orifice and pushes the lower half of the lower compressed plug out of the orifice and into the vent hole C of the can cover. As the plug leaves the orifice and passes through the vent, it immediately expands to its original size pressing against the inside surface of the can cover. The result is that there is formed an enlarged head inside the can. This holds the plug in place.

After substantially one half of the length of the plug is inside the can, the plunger I89 comes to rest. The stationary plunger thus provides a backing for the partially inserted plug, as the sleeve I1I begins to rise. The rising of the sleeve pulls loose or strips the remaining half portion of the plug from the orifice I84.. It thereupon expands into its original size and forms an enlarged head around the vent hole on the outside of the can as shown in Fig. '1;

During this stripping of the plug from the sleeve orifice, the following plug is pushed into the orifice, and the sleeve and the plunger thereafter rise in unison. The plug received in the orifice now becomes the lower plug and remains there in its compressed condition in readiness for a subsequent sealing operation. Thus each plug is inserted into its vent hole of the can by pressure exerted on it through a second plug. The inserted plug completely fills the vent hole C of the can, the middle portion of the plug between its two enlarged heads remaining in a compressed condition and thereby hermetically sealing the can.

'At this stage in the cylcle of operation on the can, the lifter plate 48 on which it rests, descends to its original position, level with the top of the machine table 43. In its lowered posi-q ,in the stationary shoe.

tion, the sealed can is adjacent a-rotatable discharge star wheel 20I '(Figs. 1 and 2) having prongs 202 whichv engage behind the sealed can and sweep it out of its turret pocket 63 and across the table to a suitable place of deposit. Guide rails-204 secured to' the top of the table are provided for directing the can along a desired path of travel.

The star wheel 20I is carried on the upper end of a vertical shaft 206 which is journaled in bearings 201 formed in the frame I5 of the machine. On its lower end the shaft carries a driving gear 208 which meshes with and is driven by the main gear 3I.

Provision is made for stopping the operation of the machine when the end of a string H of rubber isreached as when its spool I I I is emptied.

For this purpose there is provided for each sealing head G a detector device 2I0 (Fig. 2) having a stationary shoe 2H and a movable shoe 2I2- between which the string of rubber passes as it is fed down into position.

The stationary shoe 2 II is bolted to the top of the sealing head bracket 94 while the movable shoe 2I2 is mounted on a pivot pin 2I3 carried The movable shoe is held against the rubber string by a light, leaf spring 2M. The movable shoe is further provided with an angularly disposed arm 2I5. As the turret 62 rotates, each arm passes an actuaating element 2E6 of a normally closed electric detector switch 211 secured to the bracket I 64. In its normal position the arm does not engage the switch.

When a string H of rubber breaks or becomes exhausted from a spool, the associated movable shoe 2I2, under compression of the spring 2M, movesin against the stationary shoe 2 I I and this change of position raises the arm 2I5 so that it will be brought into alignment with the de-- tector switch actuating element 2I6 as it moves along. Hence when the arm passes the switch, it strikes the actuating element and thereby opens the switch. This action breaks certain electric circuits connecting with the machine" driving means and thereby stops the machine. This permits replacement of the empty spool I I I with a new filled one.

The electric circuits will now be explained and reference should be had to the wiring diagram in Fig. 8. In this diagram an electric motor is indicated by the numeral 22I and'the motor is preferably the main source of power for actuating the machine. The motor is excited from a suitable source of electrical energy such as a generator 222.

The generator is connected into a motor starting circuit which includes a lead wire 223, start switch 224, wire 225, stop switch 226, wire 221, the detector switch 2I1, wire 228, motor relay solenoid 229, and a return lead wire 23!] which connects with the generator. When the start switch 224 is momentarily closed, electric energy from the generator passes through the circuit thus established and thereby energizes the relay solenoid 229.

Energizing of the relay solenoid 229 closes a motor switch 235 and a holding switch 236 one side of which is connected by a wire 231 to the motor switch and the other side of which is connected by a wire 238 to the wire 225. Closing of the motor switch 235 connects the motor directly with the generator by way of wires 239, 240. Hence energy from the generator passes directly into the motor. It also passes along wire 231, switch 236, wires 238, 225,

stop'switch 226, ,wire '221, detector switch 2I1, wire 228, solenoid 22-9 and return wire 23! This holds the solenoid energized even though the start switch 224 is immediately released and the motor continues to operate. It is this holding circuit which is broken when the detector switch 2I1 is opened by failure of a rubber string.

When the circuit is broken the solenoid becomes deenergized. The motor switch 235 and holding switch 236 automatically open and electric energy is thereby cut off from the motor. The motor and the machine thus cease operating. This same circuit may also be manually broken when desired by opening the stop switch226.

It is thought that the invention and many of its attendant advantages will be understood from the foregoing description, and it will be apparent that various changes may be made in the form, construction and arrangement of the parts without departing from. the spirit and scope of the invention or sacrificing all of its materialadvantages, the form hereinbefore described being merely a preferred embodiment thereof.

I claim:

1.A machine for sealing vent holes in containers, comprising in combination, a rotary sealing head, means for rotating said head, means carried by said head for compressing a rubber plug into a dimension smaller than the vent hole to be sealed, instrumentalities for bodily moving said compressing means into engagement with a container to bring the compressed plug immediately. adjacent the vent hole, and elements for inserting the compressed plug into the vent hole while permitting it to expand as it is inserted so that the plug will fill and thereby seal the hole.

2. A machinefor sealing vent holes in containers, comprising in combination, means for feeding a string of resilient sealing material, means for severing sealing plugs from said string. means for moving the severed plugs transversely of the machine into registration with said vent holes, means for compressing a said plug into a dimension smaller than the vent hole to be sealed, instrumentalities for vacuumizing the container through the vent hole, and elements for inserting the compressed plug into the vent hole of the vacuumized container while permitting it to expand as it is inserted so that the plug will fill and thereby seal the hole.

3. A machine for sealing vent holes in containers, comprising in combination, means for intermittently feeding a rubber string of sealing material, means for successively cutting sealing plugs from said string of rubber, means for shifting the cut plugs laterally of the machine into registration with said vent holes, means for compressing asaid rubber plug into a dimension smaller than the vent hole to be sealed, instrumentalities for vacuumizing the container through the vent hole, means for filling the vacuumized container with a fluid under pressure, and elements for inserting the compressed plug into the vent hole of the vacuumized and fluid filled container while permitting it to expand as it is inserted so that the plug will fill and thereby seal the hole.

4. A machine for sealing vent holes in containers, comprising in combination, a sealing head movable into position over a container to be sealed, feeding mechanism for feeding a string of rubber in a step-by-step movement into said sealing head, a cutting instrumentality for severing a plug from said string, a transfer device for receiving the severed plug and for shifting it into position in alignment with the vent hole in the container, means for receiving the transferred plug and for compressing it into a dimension smaller than the vent hole, and elements for inserting the compressed plug into the vent hole.

5. A machine for sealing vent holes in containers, comprising in combination, mechanism for feeding a, string of rubber into the machine, devices for cutting off a plug from the string, means for receiving and for compressing the rubber plug into a dimension smaller than the vent 'path of travel, a sealing head movable over the path of travel of the containers, means carried by said sealing head for feeding a string of resilient sealing material, means for successively cutting sealing plugs from said string, means for moving said plugs into registry with said vent holes, means carried by said sealing head for successively receiving and compressing said plugs into a dimension smaller than the vent hole of a moving container, and elements also carried by said sealing head for inserting a said compressed plug into a said vent hole as its corresponding container moves along its path of travel.

7. A machine for sealing vent holes in containers, comprising in combination, a rotatable turret having spaced pockets for receiving and propelling along a predetermined curved path of travel, containers having vent holes in the top thereof, a plurality of sealing heads one disposed above each turret pocket and movable with said turret, a lifter plate below each pocket and movable with said turret for carrying the containers to be sealed and for raising them into engagement with said sealing heads so that the top portion of the containers will be blocked ofi from the outside atmosphere, instrumentalities for vacuumizing the interior of the containers through the vent hole in the blocked off portion of a container, means carried by a said sealing head for intermittently feeding a string of resilient sealing material, means for successively cutting sealing plugs from said string, means for successively moving said plugs into registry with said vent holes, means carried by a said sealing head for receiving and for compressing a said resilient plug into a dimension smaller than the vent hole of the container being vacuumized, and elements for inserting the compressed plug into the vent hole of the vacuumized container to hermetically seal the same.

8. A machine for sealing vent holes in containers, comprising in combination, a rotary sealing head movable into position over a container to be sealed, means for rotating said sealing head, a sleeve carried by said head having a bore therein to receive a succession of rubber plugs, said bore having a portion of reduced diameter for successively compressing the plugs into a dimension smaller than the vent hole in the container to be sealed, means for successively feeding said plugs into said sleeve bore, and a vertically reciprocable plunger disposed within said sleeve, means for reciprocating the plunger relative to the sleeve for pushing a said plug through said bore towards and partially into the reduced portion thereof, said plunger being operative by said reciprocating means on another movement in the same direction to push a, succeeding fed and positioned plug through said bore and against said first mentioned plug to force the compressed portion of the latter into inserted position within the vent hole of the container to be sealed.

9. A machine for sealing vent holes in containers, comprising in combination, a rotary sealing head movable into position over a container to be sealed, means for rotating said sealing head, said head being adapted to carry a string of rubber, means for cutting a series of plugs from said string, a vertically movable sleeve carried by said head having a bore therein to receive a succession of rubber plugs, said bore having a portion of reduced diameter for successively compressing the plugs into a dimension smaller than the vent hole in the container to be sealed, means for successively feeding said plugs from said cutting means into said sleeve bore, a vertically reciprocable plunger disposed within said sleeve, means for reciprocating the plunger relative to the sleeve for pushing a said plug through said bore towards and partially into the reduced plug compressing portion thereof, and means for moving said sleeve towards a said container to position said partially compressed plug immediately adjacent the container vent hole, said plunger being operative by said reciprocating means on another movement in the same direction to push a succeeding fed and positioned plug through said bore and against said first mentioned positioned plug to force the compressed portion of the latter into inserted position within the vent hole of the container to be sealed, said sleeve moving means being further operative to move the sleeve in the opposite direction to strip the inserted plug therefrom, whereby to condition the sealed container to be discharged from the machine.

JOHN M. HOTHERSALL. 

